Source : Webster's Revised Unabridged Dictionary (1913)

Nolle prosequi \Nol"le pros"e*qui\ [L., to be unwilling to
   prosecute.] (Law)
   Will not prosecute; -- an entry on the record, denoting that
   a plaintiff discontinues his suit, or the attorney for the
   public a prosecution; either wholly, or as to some count, or
   as to some of several defendants.

Source : WordNet®

nolle prosequi
     n : an entry in the court record to the effect that the
         plaintiff or prosecutor will not proceed [syn: {nol pros}]
     v : declare that a legal case will not be prosecuted [syn: {nolle
         pros}, {nol. pros.}]